└── JAVA code


/JAVA code:
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 1 | import java.util.*;
 2 | public class Main
 3 | {
 4 | 	public static void main(String[] args) {
 5 | 	    Scanner Sc = new Scanner(System.in);
 6 | 	    int n = Sc.nextInt();
 7 | 	    int[] a = new int[n];
 8 | 	    int i,temp;
 9 | 	    for(i=0;i<n;i++){
10 | 	        a[i] = Sc.nextInt();//input
11 | 	    }
12 | 	    for(i=0;i<n-1;i+=2){
13 | 	        temp=a[i];    //swapping
14 | 	        a[i]=a[i+1];
15 | 	        a[i+1]=temp;
16 | 	    }
17 | 	    for(i=0;i<n;i++){
18 | 	        System.out.print(a[i] + " ");//output
19 | 	    }
20 | 	}
21 | }
22 | 


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